Thermostatic device



1940- c. F. PRUTTON ET AL 2,185,421

THERIOSTATIC DEVICE Filed Feb. 16. 1955 INVENTORS Carl F. Pruttou BY Jghn T. fiarv'iu ATTORNEY Patented Jan. 2, 1940 UNITED STATES 2,185,421 THERMOSTATIO nnvrcs Cal-1F. Prutton, Cleveland Heights, and mm '1'. Marvin, Fail-view Village, Ohio, assignorl to The Patrol Valve Company, Cleveland, Ohio. a corporation of Ohio Application February 16, 1985, Serial No. 6,816.

6 Claims.

This application is a continuation in part or our copendng application 600,888, flied March 24, 1932.

This invention relates to thermostatic operating elements and in particular thermostatic operating elements which are intended for high temperature work and in which the expansion of the thermo-sensitive fluid is utilized as a. source of power.

In the construction of thermostatic devices, one of the objects ordinarily sought for is that of obtaining a considerable movement of the heat responsive element over a given temperature range; or stated in other words, sensitivity is an important factor in the construction 01' thermostatic devices.

The use of the fluid pressure thermostat has been confined principally to low temperature work for the reason that the known thermosensitive fluids previously used by others are not commercially adapted for high temperature use and are objectionable on one or more of the following grounds: high cost, low boiling point, high freezing point, low decomposition temperature, high vapor pressure, toxic properties, and for other reasons as will be hereinafter pointed out.

An object of this invention is to provide a thermo-sensitive fluid which has a. high boiling temperature, which is chemically stable at temperatures considerably above its boiling point, which has a low latent heat of vaporization, which has a low freezing point, which is non-corrosive to the metal used in the construction of the valve,

which is a non-toxic, and which is inexpensive and readily obtainable in a relatively pure state.

A further object of this invention is to provide in a device of the type described, a container for a thermo-sensitive fluid which is relatively stable to such fluid as relatively high temperatures.

Stated in general terms, our invention consists in the provision of a fluid pressure operated thermostatic valve having a heat responsive bulb which is adapted to transmit to a thermo-sensitive fluid a limited amount of the heat to which it is subjected. An important feature of our invention is the provision of a thermo-sensitlve fluid which is peculiarly adapted for high temperature work.

With these and other objects in view, the invention consists in the novel construction, arrangement and combination of parts, hereinafter described, illustrated in some oi. its embodiments in the accompanying drawing and particularly pointed out in the appended claims,-

The drawing shows an elevational view partly in section of the valve as it might be applied to a burner control.

Referring to the drawing, I indicates a gas supply line that communicates with the inlet side of thermostatic valve 2. By-pass conduit 3 under control of the valve 4 is connected with gas supply line I at a point ahead 01' valve 2 for supplying gas to a by-pass burner 5 which may be a pilot burner. A valve 6 may be employed with burner 5 as a mixing valve such as is set out in the copendlng application.

Burner 5, as will be readily understood, is designed simply to represent any type of burner and more particularly any by-pass burner. A thermostat or tip I! is in heat conducting relation with tube 20. Tube contains thermostatic fluid responsive to heat from tip IS The tip I9 and part of tube 20, if desired, may be enclosed together with burner i in a housing 2| that represents any sort of heating chamber. In other words, wall 2| may be an oven wall or it may be a pilot housing. The operation of the device is the saine whatever the wall 2| may be.

Tube 20 is connected with the interior of an expansible member 23 which may be a bellows.

nalied in bushing 26, that is received in the threaded opening 21 provided in the valve body .28. This bushing is provided with a flange or shoulder 26a by means 01' which it may be adjusted in valve body 28.

Fitting 25 is provided with a lock nut 29, which when loosened permits the adjustment of the bushing 26 and which when tightened serves to squeeze the packing washer 30 between the fitting 25 and the bushing 26 for the purpose of preventing the escape oi. gas from the interior of the valve body. .Bellows 24 is provided with an apertured cap 2|, the opening of which is onclosed by a plug 82. The aperture in the cap is provided for-the charging of the thermostat with a thermo-sensitive fluid, after which operation the plug is inserted and then sealed with solder. The filling operation is performed in such wise that no air is enclosed in the fluid container.

A cup-shaped valve head 33 isremovably carried on the upper end of the bellows 24'. Valve head 33 is provided with an annular washer 34 arranged to contact with valve seat 35 on valve body 28. A spring 36 is provided to urge the valve head toward its closed position. The spring abuts at one end against a. removable valve cap 3'! which is provided in the side of the valve which is closed by the valve cap 31 and of sufficient size to permit removal of all of the operating elements of the valve, thus facilitating both the machining and assembling operations necessary in constructing the valve.

The outlet side of the valve body 28 is connected to gas conduit 38 which in turn may be connected to any gas burner or the like kind of outlet.

It will be understood that the particular type of valve employed is of secondary importance. As here shown, the valve opens upon application of heat to the thermal bulb. It is obvious that it could be of a type to close upon increase of heat, such as are employed in oven regulators.

Heretofore, great difficulty has been involved in the use of these thermostats for, high temperature, since the liquid was subject to decomposition at high temperature. It will be understood 'that in a gas range application, the operating temperature frequently goes as high or higher than 500 to 600 Fahrenheit. The object of the research behind the present application has been to obtain a filling material'that will not thus decompose at high temperatures, and also to provide a material for the thermostatic container which will not act as a catalyst to decompose the filling material.

As set out in the parent application, several fluids have been discovered to be satisfactory. Among these are certain halogenated diphenyl compounds.

It has been determined that chlorinated diphenyl, or chlorinated diphenyl oxide possesses desirable characteristics for usein high temperature thermostats. The physical characteristics of the substances vary with the quantity of chlorine annexed to the diphenyl lattice. The boiling temperatures of these chlorinated diphenyls are found to be suitable, and they occur generally above the normal lower operating temperatures to which the thermostats are subjected. Low boiling temperatures are undesirable since they tend to cause high vapor pressures at the higher temperatures.

In connection with the use of these fillers, it has been found, as set out in the parent application, that the use of nickel or its derivativeshereinafter nickel and its derivatives or compounds will be referred to as nickelic metals for the containers is advantageous. It has been determined that some metals act as catalysts to the decomposition of the filler material, particularly at the high temperatures involved. Nickel has been found to have little, if any, catalytic action in combination with the herein described filler materials.

It will be seen that a thermal device has been provided that will withstand temperatures as high as 650 Fahrenheit Without decomposition. Also one has been provided with a filler that is non-toxic, should the container break. Likewise are not excessive so as to put unduestress on the containers. These fillers likewise have relatively low freezing points, belowthe lower normal operating range of the thermostat as herein shown or described. This last is desirable since it avoids the necessity of transiting the solid to liquid stage during the operation, which transition, if necessary, would retard the speed of operation. These fillers may be passed through their range of operation over and over again without alteration in their properties. And they are non-inflammable so that they will not explode if they spring a leak.

The invention having been described, what is claimed is:

1. In a high temperature thermostatic device of the kind described, a container adapted to be subjected to heat, a fluid therein to which the heat is to be transmitted, said fluid consisting of one of the halogenated .diphenyls that expands upon heatin and means actuated by said expansion.

2. In a high temperature thermostatic device of the kind described, a container adapted to be subjected to heat, a filler therefor comprising one of the chlorinated diphenyls that expands upon heating, and means actuated by said expansion.

3. In a high temperature thermostatic device of the kind described, a container adapted to be subjected to heat, a filler therefor comprising chlorinated diphenyl that expands upon heating, and means actuated by said expansion.

4. In a high temperature thermostatic device of the kind described, a container adapted to be subjected to heat, a filler therefor comprising chlorinated diphenyl oxide that expands upon heating, and means actuated by said expansion.

5. In a thermostatic device of the kind described, the combination of a fuel valve, a bulb adapted to be subjected to heat, an expansible and contractible chamber connected to the valve for actuating the same, a tube connecting the bulb and chamber, and chlorinated diphenyl oxide completely filling the tube and chamber as a thermo-responsive liquid, the expansion and contraction of which in response to temperature changes are communicated to the chamber for actuating the'valve.

6. In a thermostatic device of the kind described, the combination of a fuel valve, a bulb adapted to be subjected to heat, an expansible and contractible chamber connected to the valve for actuating the same, a tube connecting the bulb and chamber, and chlorinated diphenyl completely filling the tube and chamber as a thermo-responsive liquid, the expansion and contraction of which in response to temperature changes are communicated to the chamber for actuating the valve.

CARL F. PRUTTON. JOHN T. MARVIN. 

